Roger Beep - IC7000 + HM-151 installation notes

This article contains notes on installation of a Roger Beep for an Icom IC7000 transceiver for use with the standard HM-151microphone.

CAVEAT: Any modifications that you make to your transceiver are entirely your own responsibility. Owen Duffy takes no responsibility for the accuracy of this article, or for the outcome of your modifications. Modification of a transceiver may have implications for original warranty.

The HM-151 contains a microprocessor, and sends the PTT signal to the transmitter via a data line (J1 pin8). The transmitter in turn sends a normal /PTT line back to the microphone (J1 pin4) to operate the red tx LED.

The RB needs to intercept the PTT line directly after the mic PTT switch, so it cannot be simply inserted inline in the mic cord in the way that it can be with most other transmitters.

Fig 1: HM-151 circuit.

Fig 1 shows the HM-151 circuit.

There is little space inside the microphone case, and it may be difficult to fit the RB inside the case.

There is a circuit for another Roger Beep device that connects the device to the rear mic socket whilst the HM-151 is plugged into the front panel. This design causes the Roger Beep to key the transceiver up almost immediately after the transceiver switches back to receive. The approach was considered when designing the VK1OD Roger Beep but was ruled out because its may have undesirable effects if an external preamplifier, linear amplifier, transverter or other relays.


Version Date Description
1.01 03/11/2008 Initial.


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